Animal litter box

ABSTRACT

An animal litter box includes an evacuation container and a hood, the hood having a fixed hood, a movable hood, and a pair of connecting portions. The movable hood is configured to be moved rotatably either outside or inside the fixed hood such that an end edge of the movable hood is proximal to the fixed hood while maintaining a prescribed distance at least one of the fixed hood  31  and the movable hood is provided with a convex restricting portion which prevents a distance between an end edge on at least the one end of the movable hood  32  and the fixed hood  31  from being less than the prescribed distance.

CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims the benefit of priority fromJapanese Patent Application No. 2007-173554, filed on 29 Jun. 2007, thecontent of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to an animal litter box.

BACKGROUND OF THE INVENTION

Conventionally, as a litter box for animals such as cats, a litter boxhas been known which is provided with an evacuation container of whichupper surface is open and a hood covering an upper side of theevacuation container, the hood having an opening for an animal going inand out. For such an animal litter box with a hood, when cleaning up thebox, it is necessary to remove the hood or put one's hand into the boxfrom the opening formed on the hood. However, it takes much effort totake off the hood whenever cleaning up the box. Furthermore, it is hardto remove the urine or feces of the animal completely when putting one'shand into the box from the opening.

To solve the abovementioned problems, Japanese Unexamined PatentApplication First Publication No. 2002-325520 (“the '520 application”)has disclosed an animal litter box comprising a hood having a fixed hoodcovering one half of an evacuation container, and a movable hoodcovering the other half of the evacuation container. The movable hood isformed to move rotatably, and the animal litter box is configured tostore the movable hood inside or outside of the fixed hood when themovable hood is moved rotatably.

Regarding the animal litter box as described in the '520 application, aprescribed distance needs to be formed between the movable hood and thefixed hood so that the movable hood can be moved along the inner side orouter side the fixed hood. Here, in the case where the distance betweenthe movable hood and the fixed hood is reduced, when the movable hood isopened or closed, the fixed hood may be contacted with the movable hoodand the like due to small flexure or deformation of the fixed hood orthe movable hood, which causes the movable hood to be stuck. On theother hand, in a case where the distance between the movable hood andthe fixed hood is enlarged, the animal litter box cannot be sealedcompletely even though the movable hood is closed.

SUMMARY OF THE INVENTION

The present invention provides an animal litter box of which a movablehood can be opened and closed smoothly even though a distance betweenthe movable hood and a fixed hood is small.

A convex restricting portion is provided which prevents the distancebetween the movable hood and the fixed hood from being less than aprescribed distance on the fixed hood and/or the movable hood, therebyaccomplishing the present invention. More specifically, the presentinvention provides the following.

According to a first aspect of the invention, an animal litter box isprovided which comprises an evacuation container of which an uppersurface has an opening and a hood disposed above the evacuationcontainer so as to cover the opening, the hood having a fixed hooddisposed on one end of the evacuation container, a movable hood disposedon the other end of the evacuation container, and a pair of connectingportions which connect the movable hood to the fixed hood to be movedrotatably. The movable hood is configured to be moved rotatably outsideor inside of the fixed hood in the state that an end edge on at leastthe one end of the movable hood is proximal to the fixed hood withmaintaining a prescribed distance, and wherein at least one of the fixedhood and the movable hood is provided with a convex restricting portionwhich prevents a distance between an end edge on at least the one end ofthe movable hood and the fixed hood from being less than the prescribeddistance.

According to a second aspect of the present invention, in an animallitter box according to the first aspect, when the movable hood is in aclosed state, the movable hood has an overlapping portion with the fixedhood, and the pair of connecting portions is disposed in the vicinity ofan end edge of the evacuation container in the overlapping portion so asto face each other, and connects the movable hood with the fixed hood.

According to a third aspect of the present invention, an animal litterbox according to the first aspect or the second aspect has a movablehood that is configured to be moved rotatably outside the fixed hood,and the restricting part is composed of an inwardly protruding portionwhich is formed on an inner surface of an end edge on at least the oneend on an upper surface of the movable hood. On an outer upper surfaceof the fixed hood, extending from the other end to the one end, aconcave guiding groove for guiding the moving of the protruding portionwhen the movable hood is altered from a closed state to an open state isprovided.

According to a fourth aspect of the present invention, an animal litterbox according to the first aspect or the second aspect has a restrictingportion that is composed of one or more inwardly protruding portionswhich are formed on an inner surface of an end edge on at least the oneend of the movable hood.

According to a fifth aspect of the present invention, an animal litterbox according to the first aspect or the second aspect has a restrictingportion that is composed of a convexity which is formed on an outerupper surface of the fixed hood and which extends from the other end tothe one end. A guiding member with a concavity which is hollow upwardcorresponding to a convex shape of the convexity is provided on an innersurface of an end edge on at least one end of an upper surface of themovable hood.

According to the animal litter box of the present invention, a movablehood can be opened and closed smoothly even though a distance betweenthe movable hood and a fixed hood is reduced over prior art litterboxes.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will become more readily apparent from the DetailedDescription of the Invention which proceeds with reference to thedrawings, in which:

FIG. 1 is a perspective diagram of an animal litter box of the firstembodiment of the present invention, which is viewed from a front sidewith a movable hood being in the closed state;

FIG. 2 is a perspective diagram of the animal litter box shown in FIG.1, which is viewed from a rear side;

FIG. 3 is a side view of the animal litter box shown in FIG. 1;

FIG. 4 is a cross-sectional view taken along the line X-X in FIG. 3;

FIG. 5 is a partially enlarged view of a portion of FIG. 4;

FIG. 6 is a vertical sectional view in an anteroposterior direction ofthe animal litter box of the first embodiment with the movable hoodbeing in a closed state;

FIG. 7 is a vertical sectional view in the anteroposterior direction ofthe animal litter box of the first embodiment with the movable hoodbeing in an open state;

FIG. 8 is a sectional view of an animal litter box of a secondembodiment of the present invention, which corresponds to that in FIG.4; and

FIG. 9 is a sectional view of an animal litter box of a third embodimentof the present invention, which corresponds to that in FIG. 4.

DETAILED DESCRIPTION OF THE INVENTION

In the following, an animal litter box of the present invention isdescribed with reference to the drawings, based on a first embodiment,which is a preferred embodiment.

As shown in FIG. 1, the animal litter box 1 of the first embodiment isprovided with an evacuation container 2 of which an upper surface has anopening and a hood 3 disposed on an upper side of the evacuationcontainer 2 so as to cover the opening. The evacuation container 2 isconfigured to include a bottom part of which shape of the surface isrectangular and sidewalls with a prescribed height which stand in anearly vertical direction at each four sides which are the rims of thebottom part. The evacuation container 2 is a place where an animal usingthe animal litter box 1 of the present invention evacuates feces orurine, and granular materials called animal litter (not shown) can bedispersed as appropriate in the evacuation container 2.

The bottom part of the evacuation container 2 is configured to have aliquid permeable capability. In the first embodiment, as shown in FIG.1, the bottom part has a plurality of rectangular liquid permeableopenings, which makes the bottom part gridironed. The shape of theliquid permeable openings is not limited to be rectangular, and may beround, triangle, and the like. In addition, the size of the liquidpermeable openings is preferably less than the size of granularmaterials so that the granular materials dispersed on the bottom partare prevented from dropping downward through the liquid permeableopenings. A lower container 4 is disposed under the evacuation container2. A drawer tray 41 which can be taken out in a horizontal direction isprovided in the lower container 4, the drawer tray 41 which can collectliquid such as animal urine going through the bottom part of theevacuation container 2. An upper surface of the drawer tray 41 is openand a bottom part thereof is formed as a nearly rectangular shape. Inaddition, the bottom part of the drawer tray 41 is configured to belarger than the bottom part of the evacuation container 2. Furthermore,the bottom part of the drawer tray 41 can hold detachably andreplaceably an absorbent sheet (not shown) which absorbs liquid such asanimal urine going through the bottom part of the evacuation container2. In the first embodiment, the drawer tray 41 can be taken out from afront side on which an opening 321 (described later) is provided.

As shown in FIGS. 1 to 3, the hood 3 is provided with a fixed hood 31and a movable hood 32, and is configured such a manner that the fixedhood 31 is disposed on a rear side of the rectangular evacuationcontainer 2, the rear side which is one end of the longitudinaldirection, and is fixed with the evacuation container 2, and the movablehood 32 is disposed on a front side of the rectangular evacuationcontainer 2, the front side which is the other end of the longitudinaldirection, and has an overlapping portion 5 where the movable hood 32overlaps with the fixed hood 31. In addition, the fixed hood 31 isconnected with the movable hood 32 by a pair of connecting portions 33at a portion of the overlapping portion 5 where the movable hood 32overlaps with the fixed hood 31. The movable hood 32 is configured to bemoved rotatably.

As shown in FIGS. 1 and 2, in the first embodiment, the fixed hood 31covers approximately a half of the evacuation container 2 which isequivalent to the rear side of the evacuation container 2, and a topsurface of the fixed hood 31 is formed as a nearly a circular arcsurface which is curved from the one end of the front side toward theother end of the rear side. In addition, both side surfaces of the fixedhood 31 stand in nearly a vertical direction. Furthermore, the frontside and the lower side of the fixed hood 31 is open. The movable hood32 covers approximately a half of the evacuation container 2 which isequivalent to the front side of the evacuation container 2, and theexternal form is nearly a rectangular shape. That is, all of the frontsurface and both side surfaces located at the front side on the movablehood 32 stand in nearly a vertical direction, and the upper surface ofthe movable hood 32 extends in nearly a horizontal direction. Inaddition, the rear side and the lower side of the movable hood 32 areopen.

As shown in FIGS. 1 and 2, the fixed hood 31 has a protrusion part 7 onan end of the lower side of the fixed hood 31, the protrusion part whichprotrudes externally in nearly a horizontal direction from the end. Morespecifically, a rear protrusion part 71 is formed on the end of the rearside on the top surface formed with a curvature of the fixed hood 31,and protrudes externally in the longitudinal direction in nearly ahorizontal direction. In addition, a pair of fixed hood side protrusionparts 72 is formed on the lower ends of both side surfaces of the fixedhood 31, each of which protrudes externally in the width direction.

As shown in FIG. 2, a pair of stoppers 90 which protrudes upward towardthe movable hood 32 is provided on the rear protrusion part 71. Thus, byproviding the stoppers 90 on the rear protrusion part 71, a distancebetween the end of the rear side of the movable hood 32 and the rearprotrusion part 71 is maintained when the movable hood 32 is in the openstate. Accordingly, in a case where the movable hood 32 is moved from anopen state to a closed state, the movable hood 32 can be easily movedfrom the open state to the closed state by inserting one's finger intothe space. The height of the pair of stoppers 90 is preferably 5 to 35millimeters, and more preferably 15 to 25 millimeters when insertingone's finger into the space thus formed.

One of the pair of the fixed hood side protrusion parts 72 is providedwith a shovel holder 91 for holding a shovel (not shown) used whencleaning the animal litter box 1. The shovel holder 91 is providedproximal to an outer edge external to the width direction on the fixedhood side protrusion part 72 in such position so as not to be contactedwith the movable hood 32 when the movable hood is moved rotatably.

Similar to the fixed hood 31, the movable hood 32 also has a protrusionpart 7 on an end of the lower side of the movable hood 32 in the closedstate, the protrusion part which protrudes externally in nearly ahorizontal direction from the end. More specifically, as shown in FIG.1, a front protrusion part 73 is formed on the lower end of the frontside of the movable hood 32, and protrudes externally in thelongitudinal direction in nearly a horizontal direction. In addition, apair of the movable hood side protrusion parts 74 is formed on the lowerends of both side surfaces of the movable hood 32, each of whichprotrudes externally in each width direction. The front protrusion part73 further protrudes in a longitudinal direction from the center part ofthe width direction, thus constituting a hood side handle 75 (see FIG.1). With regard to the animal litter box 1 of the present embodiment,the movable hood 32 can be altered from the closed state to the openstate using the hood side handle 75. An outer rim of the hood sidehandle 75 is formed to be a convexed shape which is curved in alongitudinal direction from a view of flat surface.

The movable hood 32 is provided with the opening 321 which links aninner space of the animal litter box 1 with an outer space at the frontsurface thereof, whereby an animal can go in and out the animal litterbox 1 through the opening 321. The opening 321 may be formed as asquare, rectangle, circle, ellipse, and the like, and is not limited toany specific shape as long as it is easy for an animal using the animallitter box 1 to go in and out. In the first embodiment, the opening 321is formed to be a rectangular shape where a vertical direction is a longside of the rectangle.

As shown in FIG. 3, the fixed hood 31 and the movable hood 32 have theoverlapping portion 5 where an end edge of the front side of the fixedhood 31 overlaps with an end edge of the rear side of the movable hood32 when the movable hood 32 is in the closed state. In addition, theoverlapping portion 5 is formed in such a manner that the movable hood32 is located outside of the fixed hood 31. Furthermore, the pair of theconnecting portions 33 is provided at end edges of the lower containerin the overlapping portion 5, facing each other. Thus, the animal litterbox 1 of the first embodiment is configured such that, in a case wherethe movable hood 32 is altered from the open state to the closed state,the movable hood 32 which is located outside of the fixed hood 31 can bemoved rotatably with the pair of the connecting portions 33 operating asan axis. In addition, the pair of the connecting portions 33 may connectthe movable hood 32 with the evacuation container 2 so that the movablehood 32 can be moved rotatably.

As shown in FIGS. 3 to 6, regarding the animal litter box 1 of the firstembodiment, when the movable hood 32 is in the closed state, an end edgeof at least the rear side of the movable hood 32 is proximal to thefixed hood 31 while maintaining a prescribed distance to the fixed hood31. That is, an inner surface of an end edge of the rear side of themovable hood 32 lies in a vicinity of an outer surface of the fixed hood31. In addition, as shown in FIG. 3, the top surface of the fixed hood31 is configured as nearly a circular arc surface of which radius isfrom the connecting portion 33 to the end of the top surface. Therefore,in a case where the movable hood 32 is moved from the closed state tothe open state, the movable hood 32 is configured to be moved outside ofthe fixed hood 31 with an end edge of at least the rear side of themovable hood 32 being proximal to the fixed hood 31 while maintaining aprescribed distance to the fixed hood 31 (see FIGS. 6 and 7). Inaddition, the movable hood 32 is formed to be approximately rectangularin the first embodiment. Therefore, in a case where the movable hood 32is altered from the closed state to the open state, only a part in avicinity of an end edge of the rear side on the upper surface of themovable hood 32 is moved rotatably with the part being proximal to thefixed hood 31. On the other hand, a rest other than the part in avicinity of an end edge of the rear side on the upper surface of themovable hood 32 is moved rotatably with the rest being away from thefixed hood 31.

The fixed hood 31 and/or the movable hood 32 are provided with a convexrestricting portion 6 which prevents the distance between an end edge ofat least the rear side of the movable hood 32 and the fixed hood 31 frombeing less than a prescribed distance. In the first embodiment, as shownin FIGS. 4 to 6, the restricting portion 6 is composed of an inwardlyprotruding portion 61 which is formed on an inner surface of an end edgeof the rear side on the upper surface of the movable hood 32.

Thus, by providing the convex restricting portion 6 to the fixed hood 31and/or the movable hood 32, a distance L1 where the restricting portion6 is provided between the movable hood 32 and the fixed hood 31 is lessthan a distance L2 where the restricting portion 6 is not providedbetween the movable hood 32 and the fixed hood 31. Accordingly, even ina case where the movable hood 32 or the fixed hood 31 is deformed suchas by flexure, the movable hood 32 and the fixed hood 31 are contactedonly at the restricting portion 6, thereby preventing those hoods frombeing closer to each other. Consequently, it can prevent the movablehood 32 from being stuck when it opens and closes, or it can preventboth hoods from being damaged by friction due to the movable hood 32 andthe fixed hood 31 being in significant contact with each other.

The distance L2 where the restricting portion 6 is not provided betweenthe inner surface of an end edge of at least the rear side of themovable hood 32 and the outer surface of the fixed hood 31 is preferably1 to 10 millimeters, and more preferably 1 to 5 millimeters from thestandpoint of sealing of the animal litter box 1 when the movable hood32 is in the closed state. The distance L1 where the restricting portion6 is provided between the movable hood 32 and the fixed hood 31 ispreferably 0 to 3 millimeters, and more preferably 0 to 1 millimeter.

As shown in FIG. 2, in the first embodiment, a concave guiding groove 80for guiding the moving of the protruding portion 61 when the movablehood 32 is moved from the closed state to the open state is provided onthe outer upper surface of the fixed hood 31. The guiding groove 80,extends from the front side to the rear side, is formed at nearly acenter part of the width direction on the top surface of the fixed hood31, and is formed linearly along a curved shape of the top surface fromthe end of the front side to the end of the rear side.

It is preferred that width of the guiding groove 80 is formed broaderthan that of the protruding portion 61 from the standpoint of preventingslippage in the width direction when the movable hood 32 is opened orclosed. More specifically, it is preferably 15 to 50 millimeters. Thedepth of the guiding groove 80 is preferably 5 to 20 millimeters, andmore preferably 5 to 10 millimeters. In addition, from the standpointdescribed above, it is preferred that a distance L4 in a horizontaldirection between the protruding portion 61 and the guiding groove 80 isless than a distance L3 in a horizontal direction between the movablehood 32 on the side surface of the hood 3 and the fixed hood 31 of thehood 3 (see FIG. 5).

As a constituent material for the evacuation container 2, the lowercontainer 4, and the hood 3 which configures the animal litter box 1 ofthe first embodiment, any type of material which is normally used for ananimal litter box may be used without any limitation. For example,synthetic resins such as polyethylene and polypropylene may be used.

According to the animal litter box 1 of the first embodiment with theabovementioned configuration, by providing the convex restrictingportion 6 to the movable hood 32, even in a case where the movable hood32 or the fixed hood 31 is deformed such as by flexure, the movable hood32 and the fixed hood 31 will generally be contacted only at therestricting portion 6, thereby preventing those hoods from being closerto each other at other positions. Consequently, the present inventionprevents the movable hood 32 from being stuck when it opens and closes.Therefore, the movable hood 32 can be opened and closed smoothly eventhough a distance between the movable hood 32 and a fixed hood 31 isreduced relative to prior art designs.

In addition, a concave guiding groove 80 for guiding the moving of theprotruding portion 61 when the movable hood 32 is moved from the closedstate to the open state is provided on the outer upper surface of thefixed hood 31. The guiding groove 80 extends from the front side to therear side. Therefore, it can prevent from slippage in the widthdirection when the movable hood 32 is opened or closed, whereby themovable hood 32 can be opened and closed smoothly.

Next, the second embodiment and the third embodiment for an animallitter box of the present invention are described. Regarding the secondembodiment and the third embodiment, differences from the firstembodiment are mainly described, and the same reference numerals havebeen retained for similar parts so as to omit overlapping descriptions.Thus, unless otherwise noted, the second and third embodiments aresimilar to the first embodiment.

An animal litter box 1 of the second embodiment is mainly different fromthat of the first embodiment with regard to the number of restrictingportions 6 with which are provided. Regarding the animal litter box 1 ofthe second embodiment, the restricting portion 6 is composed of one ormore inwardly protruding portions 61 which are formed on an innersurface of an end edge of at least the rear side of the movable hood 32.More specifically, as shown in FIG. 8, three protruding portions 61 areprovided on the upper surface and both side surfaces of the movable hood32. In the second embodiment of the present invention, the fixed hood 31is not provided with the guiding groove 80.

According to the animal litter box of the second embodiment, theprotruding portions 61 which are the restricting portions 6 are providedto the upper surface and both the side surfaces of the movable hood 32respectively. Therefore, it can prevent the movable hood 32 fromslippage in a vertical direction and a width direction (a horizontaldirection) without requiring the guiding groove 80 on the fixed hood 31,whereby the movable hood 32 can be opened and closed smoothly.

An animal litter box 1 of the third embodiment is different from thefirst embodiment in that the restricting portion 6 is provided on thefixed hood 31 and the guiding member 81 is provided on the movable hood32. As shown in FIG. 9, regarding the animal litter box 1 of the thirdembodiment, the restricting portion 6 is composed of a convexity 62which is formed on an outer upper surface of the fixed hood 31 and whichextends from the front side to the rear side. The convexity 62 is formedat nearly a center part of the width direction on the top surface of thefixed hood 31, and formed linearly along a curved shape of the topsurface from the end of the front side to the end of the rear side. Inaddition, on an inner surface of an end edge of at least the rear sideof the movable hood 32, the guiding member 81 with a concavity which ishollow upward corresponding to a convexed shape of the convexity 62 isprovided.

Therefore, the animal litter box 1 of the third embodiment can have thesame effect as that of the first embodiment.

An animal litter box of the present invention is not limited to theabovementioned embodiments, and can be modified as appropriate withoutdeparting from the scope of the present invention. For example, in thefirst embodiment to the third embodiment, although the movable hood 32is configured to be moved rotatably outside of the fixed hood 31, themovable hood 32 may alternatively be configured to be moved rotatablyinside of the fixed hood. In this case, the restricting portion 6 can beprovided either on an inner surface of the movable hood 32 or on anouter surface of the fixed hood 31.

In addition, in each of the embodiments from the first embodiment to thethird embodiment, although the movable hood 32 is disposed on the frontside of the evacuation container 2 and the fixed hood 31 is disposed onthe rear side of the evacuation container 2, the movable hood 32 may bedisposed on the rear side of the evacuation container 2 and the fixedhood 31 may be disposed on the front side of the evacuation container 2.In addition, in any one of the first through third embodiments, the topsurface of the movable hood 32 may alternatively be configured as nearlya circular arc surface, which is similar to that of the fixed hood 31.

In the first embodiment and the second embodiment, as an alternative toforming protruding portion 61 on the inner surface of an end edge of therear side on the upper surface of the movable hood 32, the protrudingportion 61 may be formed so as to extend from an end of the rear side toan front side on the inner surface of an end edge of the rear side onthe upper surface of the movable hood 32. In addition, in the secondembodiment, although the protruding portion 61 which is the restrictingportion 6 is provided on the movable hood 32, the protruding portion 61may alternatively be provided on the fixed hood 31.

In addition, in the first embodiment to the third embodiment, althoughthe evacuation container 2 is provided with the bottom part having aliquid permeable capability and the lower container 4 is disposed underthe evacuation container 2, the evacuation container 4 may be without aliquid permeable capability or the lower container 4 may not be disposedunder the evacuation container 2.

An animal litter box of the present invention may be used as a litterbox for an animal kept as a pet such as cats, dogs, rabbits, and thelike. Specifically, an animal litter box of the present invention can bepreferably used as a litter box for a cat kept indoors.

1. An animal litter box comprising: an evacuation container of which anupper surface has an opening; and a hood disposed above the evacuationcontainer so as to cover the opening, the hood having a fixed hooddisposed on one end of the evacuation container, a movable hood disposedon the other end of the evacuation container, and a pair of connectingportions which connect the movable hood to the fixed hood to be movedrotatably, wherein the movable hood is configured to be moved rotatablyoutside or inside the fixed hood in the state that an end edge on atleast one end of the movable hood is proximal to the fixed hood whilemaintaining a prescribed distance between the fixed hood and the movablehood, and wherein at least one of the fixed hood and the movable hood isprovided with a convex restricting portion which prevents the distancebetween the end edge on at least the one end of the movable hood and thefixed hood from being less than the prescribed distance.
 2. An animallitter box according to claim 1, wherein, when the movable hood is in aclosed state, the movable hood has an overlapping portion with the fixedhood, and wherein each one of the pair of connecting portions isdisposed near an end edge of the evacuation container in the overlappingportion so as to face the other connecting portion, and connects themovable hood with the fixed hood.
 3. An animal litter box according toclaim 1, wherein the movable hood is configured to be moved rotatablyoutside the fixed hood, wherein the restricting portion is composed ofan inwardly protruding portion which is formed on an inner surface at anend edge on at least the one end of the movable hood, and wherein, on anouter upper surface of the fixed hood, a concave guiding groove isprovided for guiding the moving of the protruding portion when themovable hood is moved from a closed state to an open state is provided.4. An animal litter box according to claim 1, wherein the movable hoodis configured to be moved rotatably outside the fixed hood, and whereinthe restricting portion is composed of one or more inwardly protrudingportions which are formed on an inner surface at an end edge on at leastthe one end of the movable hood.
 5. An animal litter box according toclaim 1, wherein the movable hood is configured to be moved rotatablyoutside the fixed hood, wherein the restricting portion is composed of aconvexity which is formed on an outer upper surface of the fixed hood,and wherein a guiding member with a concavity which is hollow upwardcorresponding to a convex shape of the convexity is provided on an innersurface at the end edge on at least the one end of the movable hood.